Posted: 10:38, July 7, 2022 | Updated: 10:39, July 7, 2022
A huge asteroid the size of a London bus will make an extremely close approach to Earth today, despite only being spotted a few days ago. The asteroid, called 2022 NF, will come within 54,843.9 miles of our planet at around 2.45pm BST, according to NASA. To put that in perspective, that’s a little more than a quarter of the distance of the Moon at its closest point to Earth, which is 225,623 miles away. Fortunately, NASA calculations show that the massive space rock will safely pass our planet – although the space agency has not ruled out the possibility of an asteroid collision in the near future. The asteroid, named 2022 NF, will come within 54,843.9 miles of our planet at around 2:45pm BST, according to NASA (stock image)
What is a “potentially hazardous” asteroid?
A potentially hazardous asteroid (PHA) is an asteroid whose orbit comes closer than 0.05 AU (about 7.5 million km) from Earth.
It is also at least 100 meters (300 ft) in diameter.
The International Astronomical Union claims there are about 1,500 potential hazardous asteroids.
Although they do not pose a threat to Earth yet, such a large asteroid has the potential to wreak havoc if it lands on our planet, especially in populated areas.
It is believed that one hits the Earth once every 200-300 years.
2022 NF was discovered using data from the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) – a system of cameras and telescopes based in Hawaii.
Despite making its closest approach to Earth today, surprisingly the asteroid was only identified on July 4th.
The measurements show the asteroid to be between 17.7 and 39.3 feet (5.4 and 12 meters) in diameter.
At the highest end of this estimate, the 2022 NF is roughly the same size as the original Routemaster London bus!
During its close approach, the asteroid will travel at a breakneck speed of 24,606 miles per hour – about 12 times faster than a bullet.
While the chance of this asteroid hitting Earth is extremely low, NASA has not ruled out the possibility of an asteroid collision in the near future.
NASA discovers about 30 new “near-Earth objects” (NEOs) every week, and by early 2019 had discovered a total of more than 19,000 objects.
However, the space agency has warned that the catalog of NEOs is not complete, meaning an unforeseen impact could happen “at any time”.
NASA explained: “Experts estimate that an impact of an object the size of the one that exploded over Chelyabinsk, Russia in 2013 – about 55 feet (17 meters) across – occurs once or twice a century.
2022 NF was discovered using data from the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) – a system of cameras and telescopes based in Hawaii
“Impacts of larger objects are expected to be much less frequent (on the scale of centuries to millennia).
“However, given the current incomplete catalog of NEOs, an unforeseen impact – like the Chelyabinsk event – could occur at any time.”
To help prepare for such an impact, NASA recently launched its first “planetary defense” spacecraft to deflect an asteroid 6.8 million miles from Earth.
The $325m (£240m) Double Asteroid Redirect Test (DART) mission launched in November 2021 and will take 10 months to complete its nearly seven million mile journey through deep space.
The probe will crash into the small asteroid Dimorphos, which is orbiting a larger asteroid called Gemini, at a speed of 24,100 km/h in September 2022.
When the 1,210-pound space probe hits Dimorph, the plan is to change the speed of the “moon” by a fraction of a percent, echoing the plot for the Bruce Willis movie “Armageddon.”
Although the 525-foot-wide space rock poses no danger to Earth, NASA wants to measure the asteroid’s altered orbit caused by the collision.
This demonstration of “planetary defense” will inform future missions that could one day save Earth from a deadly asteroid impact.
WHAT IS NASA’S DART MISSION?
DART will be the world’s first planetary defense test mission. It is headed for the small moon asteroid Dimorphos, which orbits a larger companion asteroid called Gemini. When it gets there, it will purposely crash into the asteroid to alter its orbit slightly. While neither asteroid poses a threat to Earth, DART’s kinetic impact will demonstrate that a spacecraft can autonomously navigate to an asteroid target and kinetically strike it. Then, by using Earth-based telescopes to measure the impacts of the impact on the asteroid system, the mission will enhance modeling and forecasting capabilities to help us better prepare for a real asteroid threat should one be discovered. DART will arrive at Dimorphos in October 2022, where it will deliberately hit the asteroid at speeds of 15,000 mph. This collision will change the speed of Dimorphos in its orbit around Gemini by a fraction of a percent, changing the orbital period by several minutes
